Deca-Deku
by TenniverseTurbo20
Summary: You know how Izuku Midoriya has the power of the world's greatest hero All Might? Well, let's see how things would play out if he had the power of another great hero: Ben Tennyson. Check your watch. Why? Because for Deku, it's Hero Time! (Cover image belongs to BlueIke: https:/DeviantArt.com/BlueIke)
1. Chapter 1: And Then There Was Deku

Chapter 1: And Then There was Deku.

Hero. A name that can mean so much. But for the sake of argument, let's just shorten the term to something simpler, say someone with extraordinary power and the moral compass to use it correctly.

Sure, that term is still a little vague, but it certainly makes my job easier, doesn't it? Anyway, let's enjoy a story as old as time: an underdog rising up from the cruel hand fate dealt him.

We begin in a rather obscure place in China, the moment where things changed quite a lot. You know how parents always say that their little baby boy or girl is glowing with health? Well, not to be that guy, but one little toddler was his own nightlight from the day he was born.

Quite a lot has happened since then, namely the fact that in all the world, more and more people like that baby started to pop out of the woodwork. Not saying that every became a living searchlight, but rather folks with extraordinary abilities, goodness there should be a league of such gentlemen.

Regardless, the official name for such amazing traits over the years became Quirks. Quite the notable term, isn't it? No one power is quite like the same, each having a different name.

But anyway, so many things were done to regulate these herculean beings, but thankfully nothing too extreme. Just making an organization or two, that's all. One for the heroes and the others for...less than admirable people.

Our story begins with two people of interest. One is the greatest hero of this generation,while the other is but a humble admirer of his work.

The boy's name? "Izuku!" a voice shouted from the other room. The one who shouted his name was Inko Midoriya, a single mother with a single child.

Such an energetic boy too, he was sitting in the chair rather impatient, but still keeping his enthusiastic spirit within him.

It was almost a tradition of the young Midoriya to be glued to his seat as he fervently watched his idol do what he does best: Being a hero!

Remember what I said about the world's greatest hero? Granted, it's the name of a rather obscure TV show (I think), but it's also the title of one particular hero: All Might!

Such a name held such power, majesty, and made it clear to all that this man meant business in the field.

He was also the one saving quite the haul of civilians from a burning wreck in the video Izuku's eyes were glued to at that very moment.

It was like he was a demigod, having quite the sturdy frame on him with the brawn to match, but he also had quite the charm as well. Why, with just a simple phrase people turn their heads and look up to their bronze skinned savior.

"I am here!" The great man proclaimed, carrying all of the innocent people like they were nothing as he got them to safety.

That really got Izuku becoming more excited as he gripped his All Might action figure for dear life as the video played on.

"Okay, Deku, that's enough All Might for one day." Inko said, trying to quell her squirming son, but the boy simply squealed like a pig with delight.

Uncontrollably tossing his hands in the air, letting his All Might figure drop to the floor, the young Midoriya stated his hopefully unwavering life goal, "I wanna be the best hero of all time, just like All Might!"

Almost on cue, a quick visit to the doctor kind of took the wind from Izuku's sails.

"Sorry, can't get a quirk." The doctor almost instinctively stated to the Midoriyas. Inko asked how this could be and the answer was made crystal clear.

Among Quirk Wielders, something so simple as some slight differences in joints made it possible to bear the powers others could only dream of.

Unfortunately for Izuku, though, such a trait seemed far beyond his grasp. Quirk wielders had a single joint in their pinky toe, he had two.

Normally news like that would make a child like young Midoriya grow up to be a problematic, unapologetic problem child with a sense of entitlement miles wide. Thankfully, such a fate never befell him, his "friend" Katsuki was already crazy enough. That blonde boy had the same amount of admiration for All Might as he did messing with Izuku. It was a wonder he didn't grow to become a villain with his explosive Quirk, but that's not who we're here to see.

Instead, Izuku found himself in a bit of a wreck after learning that his dreams were all but crushed by his own genes.

Almost a decade passed, give or take six full years actually, and Izuku still held onto that tiny nugget of hope lodged in the confines of his soul. No matter how many times he was ridiculed by his fellow classmates (usually led by Katsuki), he still hoped he could become a hero.

As fate would have it, however, help would come not from the world around him. No, the help Izuku needed came from the stars above.

With a stream of light and a ball of fire, the harbinger of Izuku's destiny lied just outside. Thankfully, Mrs. Midoriya was quite the heavy sleeper as not one sound caused her to stir from her mattress.

The young boy followed where the glowing green fluorescent light began to grow, and sure enough, with the meticulous maneuvering that only a growing child on the cusp of puberty can muster, he found it.

All he had to do was go into the crater and grab it, regardless of how foreboding it seemed. However, Izuku felt a sense of foreboding as he got closer to the device.

"This isn't right, I should try and bring this to the cops or something", He commented. Another part of him also felt anxious, determined to analyze this gadget and what it could bring.

Would what was inside make Izuku the hero of his dreams? Maybe a monster the likes the world had never seen?

There was only one way to find out…


	2. Chapter 2: DNA and Decisions

Chapter 2: DNA and Decisions

Inko Midoriya slept rather well all things considered. However, what woke her up one night would certainly come as a bigger shock than standing in the middle of a thunderstorm.

It's normal to see kids up past their bedtimes, but to see them up and disappear would cause any parent to start sweating more than a marathon runner on a hot summer day.

Mrs. Midoriya looked high and low for her only son, almost to no avail. I say almost because, among her constant surveillance in finding Izuku, Inko saw a rather peculiar sight in her living room.

At first, she thought it was because that person saw Izuku got kidnapped or something, but upon further examination, she learned that something even stranger happened to her son.

How did she know? She couldn't find him anywhere else and a peculiar trait a new little visitor had, particularly an incessant amount of mumbling, was a dead ringer for Izuku's usual trains of thought.

It wasn't just the mumbling that tipped Inko off, but rather the big pile of paper on the table, a closer look revealed that it was the usual math assignments they handed out in elementary school.

What surprised Inko was that each one had rather complex solutions for the otherwise simple problems on them.

"I'm sure I can crack this conundrum!" The boy thought aloud, pacing back and forth, unaware that his mother was watching from a safe distance.

The problem in question wasn't math related, as the papers on the table showed, but something else.

All Mrs. Midoriya could say to all this was "Wow", before the walking frog formerly known as Izuku turned his head towards her

"Mother?" Was all Izuku could say as he looked at Inko with hesitation, doubt, and a small amount of fear.

Thankfully, that one word was all she needed to hear to deter any doubt Mrs. Midoriya had.

"I'd love to hug you, but I think would need my oven mitts to even hold your hands without crushing you," Inko commented, giving a small chuckle as she looked at her son with a bit less anxiety.

Realizing the rare opportunity laid out before her, the doting mother of a new hero then sprang to action as she shouted, "Lemme go get the camera!"

As his mother left, Izuku found himself grateful that he mustered up the courage to take a closer look at that thing that landed in his backyard.

The strange green pod opened up as Izuku came closer, revealing something quite uncommon: "A watch?" He asked, trying to get a better look it.

As he did so, however, the strange device soon latched onto him like a lamprey on a common fish. Thankfully, unlike that parasitic menace, this simple trinket had no ill intent for its host.

That's not to say it didn't leave any lasting effects either as immediately after it latched onto him, Izuku felt rather uneasy.

Maybe it was the lack of sleep or something he ate as far as he knew. To those beyond this earth it would be child's play to piece together this device was, for lack of a better term, out of this world.

Izuku didn't care, however, as he was both joyful that his dream came true and yet felt uneasy due to how he came accomplished it.

But as soon as it came, however, it disappeared immediately after. A flashing red light emanated from the strange insignia on his back, accompanied by an alarm just loud enough for Mrs. Midoriya to rush on over.

Before the doting parent could catch a single second of her son in his new form, a crimson flash appeared, leaving behind Izuku in his natural state, thankfully away from the table due to falling on his face from it.

The only difference, however, was that a peculiar little thing was on his wrist. It was rather detailed too, with buttons, knobs, and so much more important stuff having a nifty emerald green covering it all.

Such a device was perfect for a growing boy, just as long as that boy wasn't Katsuki that is. Regardless, Inko took a closer look (more or less) at the watch, surprised to see it.

"How did you get this, honey?" Mrs. Midoriya asked her baby boy, to which Izuku frantically tried to explain with the newly expanded vocabulary he gained from his diminutive form.

The best he could manage without sounding ridiculous was, "A meteor fell into our yard and I wanted to bring its contents to the authorities in case of emergency."

Inko simply laughed a little, taking a bit of delight from her delightfully awkward son. "I bet I can figure out what that thing is." She told him, using that warm-hearted smile Izuku loved.

Lost for words, she tried to explain the strange thing on her son's wrist as best she could too, falling into the same trap as Izuku.

After a minute or two, Inko finally came up with an explanation as to what Izuku found. "It's probably some experimental device that's meant to help Quirkless people protect themselves better in case of emergencies." She told her son.

Thankfully, Izuku came to the same conclusion, but in his own words. "An experimental artificial Quirk generator, you say? That's...kinda neat."

Mrs. Midoriya simply nodded and laughed a little, thankful her son had some of his dad's brains in him, even if was the residue of some strange device. That last sentence showing it finally slipped away, but nevertheless, Inko was proud.

"I think it's the universe giving us a sign, one that says you can become a hero one day. You just gotta figure out the perfect time to use it." Inko replied before she tried getting the camera ready again.

Before they could try to record Izuku's remarkably brainy Quirk again, Izuku pressed the same button that he did before.

As he did so, he tried to see what else this thing on his wrist could do, seeing strange silhouettes as he turned the dial.

Being an otherwise simple-minded kid, the young boy saw no harm in seeing what these strange new things could yield.

When Inko was finally ready to record, she wasn't greater by her otherwise normal son, but by a new abnormality. Thankfully it wasn't another small frogman, nor was it on fire, but still had quite the strange appearance, what with having an extra pair of arms to its name.

Unlike last time, Inko was better adjusted to strange new things. In fact, this just made her perk up even more.

"A Quirk like Fourth Kind? That's even better!" She gleefully shouted, ready to see what Izuku could do now.

The crimson-skinned creature (formerly known as Izuku) looked more like a brawny bald man than anything else in terms of height.

Not only that, but he was rather nicely built, giving a clear indication that this was a super strong form.

"O-okay here goes," Izuku said, still carrying his usually social awkwardness in his voice. As he said that, he lifted the living room couch in one arm and the love seat in another.

"Wow, I'm actually doing this." Izuku thought aloud. Seeing another chair or two, he decided to try his hand at juggling, much to the amazement of his mom.

Deciding that it was enough fun for one night, having gotten all the footage she needed, and because they both needed sleep, Inko told her son "Time for bed!"

A dismayed sigh was all Izuku could offer in response as he carefully caught the chairs in midair with all but one of his arms.

Thankfully, a smile from his mom made Izuku warm up a little as he walked with her back inside, just in time for the second form to wear off as well.

Inko helped her son navigate the house in his taller stature, then helped him find comfort in his bed despite his new height.

She soon realized that in a way her son is right, this device might be dangerous if he wasn't too careful with it.

The next day, namely two pm on Monday, Inko's mind was still trying to solve this dilemma her son had. Who knows what other Quirks would spring from this device? One of them could potentially become a vengeful poltergeist that hunts humans indiscriminately or burn the country down with the right amount of wrong steps.

The only solution she figured would work was talk to the family doctor again after all these years.

"Hello? Doctor Tsubasa here." The voice on the other line said, a bit groggy from how late at night it was. In her fervent glee, Mr.s Midoriya gushed over the new twist to her life, all amounting to her saying, "Izuku has powers, Izuku has powers!"

Thankfully, Inko realized how loud she was and calmed down enough and actually tried explain the situation to the good doctor instead of yelling his ear off in unbridled glee. "Sorry, it's just that I'm so excited for my little boy, you know?" She explained, apologizing for her previous outburst.

Rubbing some wax out of his ear, Dr. Tsubasa weakly replied, "Gee, I hadn't noticed before." Clearing her throat, Inko then did a better job to explain herself, "You know how Izuku couldn't get a Quirk? Well, what if I told you that he found a new way to get one?"

The old man rolled his eyes and thought, _I would say you're absolutely crazy,_ but he knew better than to say that, he was a man of medical science after all. "Continue," Tsubasa said, deciding to indulge one of his patients' claims.

Inko then went on about what she bore witness to the previous night, including the testament Izuku gave and sent a picture or two she took. "So, that's the long and short of it, doctor. This thing could help Izuku be a hero and it could revolutionize the world." Inko said, trying to win over the curmudgeon.

Tsubasa, however, decided to cut straight to the point, "Ma'am, your son probably came across something that either of us can hardly comprehend, I would've known about something like this a while ago from the higher-ups. You should definitely be more careful around this...Quirk generator, you said? Just tell your son to turn that thing in and that he can get a decent job as an insurance agent. That could help him maintain a decent life without a quirk."

This statement lingered in Inko's mind as she hung up the phone and headed outside, figuring she needed some fresh air and more space to help think things over.

The afternoon sunlight hit the struggling mother in the face, almost as hard as the facts Dr. Tsubasa gave her not too long ago. Thankfully, it was a half hour before Izuku needed to be picked up from school, giving Inko more time to think as she got ready.

 _What should I tell him? Should I tell him to turn it in? Do I tell him to keep his new powers a secret?_ Inko lingered on these two thoughts for a minute or two, trying to decide what was the best course of action to take after she picked up her son from school.

A third thought popped up as she got into the car and started it up, _If I do, it'll break his little heart, but neither option is the better choice either way._

Driving to school like she did when her son was a kindergartener, Mrs. Midoriya took a deep breath in and decided to have a talk with her son as soon as they got home.

Speak of the devil, it was around that time that she saw Izuku walk up to the passenger door and waved.

No doubt the signal that school was done for the day, Inko unlocked the door and told her son, "Get in, honey."

As the two took their time, the mother did her best to look calm and happy for her son. Izuku thankfully broke the ice building in the car by telling her about his day.

Izuku shook his head all giddy with excitement, "They all said how shiny my watch was. Kacchan was still kinda grouchy, though." He explained, chuckling slightly at that last part.

With some more weight on her shoulders, Inko figured the best course of action would be to lighten the mood with a tried but true method that most use to diffuse bad news.

Namely, treat the blooming young lad with a friendly little trip to the local ice cream joint. As the two sat there in the thankfully warming up weather, the mother and son duo felt rather relaxed.

Izuku couldn't have been happier, he had a Quirk inside him, a new set of potential friends, and little scamp (a useful term I use loosely) Katsuki even gave him some respect by not treating him like a second-class citizen for the time being.

Given all that, and seeing the sweet little smile on the face of her sweet little boy, Inko took a deep breath again. _I don't care what that doctor said, I'm going to make sure he never cries again!_ She thought, deciding to damn her pride and tell Izuku exactly what he needed to hear.

"Honey, I called the doctor about what happened last night and he said…" She froze up for a second before Izuku quizzically looked at her.

"What? What did he say?" Izuku asked, nervous yet excited, hanging on the edge of his seat in an almost literal sense.

"He said 'you better keep that watch, son. Who knows what might happen if it fell into the wrong hands?" Inko answered, doing her best to hug her son without spilling his cone or turning on the watch.

At best, Izuku was shocked, at worst he felt confused.

With newly invigorated hope for his future, Izuku was ready for what was to come.

Either way, Inko didn't care, she got to help her son be happy again. That's all that mattered to her in the long run.

To find out more about what this choice yielded, let's peek a little closer ahead, shall we?


	3. Chapter 3: Genetic Journals

Chapter 3: Genetic Journals

It wasn't until Friday morning that Izuku finally garnered the unwanted attention of his school's faculty, for better or worse. Why? A sudden influx of straight "A"s on an elementary school report card would make anyone suspicious, especially if the person in question was the **supposedly** quirkless Izuku.

Papers with the messy scrawl of the elementary school student in question were strewn about the table, each coming from not only tests, but also homework assignments and the like.

Nothing about this sudden outcome made sense and the teachers made it their goal, no, their **mission** to crack the code as to why this happened.

"How is Midoriya doing so well now? Is he using one of the students to help him study or something?" One of the teachers commented.

Another one asked, "What if that thing on his wrist is some sort of special small computer?" This argument was shot down by, "I never heard of a support item like that, last I checked anyway."

A seemingly endless stream of questions of this caliber buzzed around in the confines of the faculty lounge. Unstoppable, that is, until one voice cried out, "If he's doing so well, let me ask him about it." Everyone turned their heads towards the one who spoke up, namely the substitute teacher.

"Someina? But you're a substitute. How do we know you won't slip up?" A portly middle-aged man asked.

"Uh, no offense, but we don't usually let substitute teachers look into this kind of thing." Another one of the teachers says bluntly.

A gentle chuckle came from Taro, who simply replied, "You're supposed to be the one teaching science, don't you remember the method of getting answers, bud?"

A stunned look was what the balding, bulbous skeptic could muster as he stood with his mouth agape.

"Figures, just let me talk to the kid and I'll get the answers you desperately need to know. It's so simple, even someone like you could do it, big guy." Someina stated as he walked out the door with a smug grin.

Another teacher, a woman, asked, "Wait, what are you gonna do?" "My job." Was all that could be said before he walked out the door.

During their squabble, Taro was the only one to notice a rather peculiar piece of paper, the back littered with a multitude of unfathomable questions and equations. And what was the name of this astounding discovery, you may ask? " _The Explanation on What Happened to Me, by Izuku Midoriya._ "

Why did Izuku write that atop his handiwork, you may ask? It was his hope that someone could at least understand who left behind such advanced mathematics or maybe help him somehow grasp the questions he couldn't solve alone.

The saddest thing was that such a compilation was left unfinished and thus unsolved. Mr. Someina planned to rectify this the only way he knew how.

"Mr. Midoriya, could you step out into the hall, please?" He asked, opening the door to his student's classroom just a crack.

A choir of "ooh"s echoed through the class, no doubt from misunderstanding. "Jeez, Deku, what did you do?" One of the students asked. "Probably gonna get a lecture from all the scores he's gotten lately." Another one replied.

Before anyone else could throw another accusation on the table, Mr. Someina groaned and stated to his class, "I just wanna talk to Izuku about something, kids, calm down." The class immediately settled down after hearing Someina's words. Amazing what the authority of a teacher can do, isn't it?

Anyway, the young boy was understandably anxious like his classmates about why he was sent out to the hall. "Mr. Someina, what's this about?" he asked.

Reaching into his coat pocket, the substitute pulled out a rather interesting piece of paper. "Oh man, I did that bad on last week's pop quiz?" Izuku asked, before realizing who's sloppy handwriting it actually was.

"Poor Kacchan", he remarked, which then got Taro realizing, "Oops, dug into the wrong pocket." Digging around, he finally found the paper in question in his back pocket.

A rather embarrassed, but still determined, Someina then started his investigation. His opening statement was as such, "Okay, champ, mind telling me why this was on the back of your worksheet? Not a lot of kids in that class could even begin to grasp the math that was poured into it, not without some pretty lengthy and pricey tutoring anyway."

Finding himself in a tight pinch, but with someone that seemed trustworthy, Izuku came clean. Besides, the truth was much better for his record than detention, after school work, or worst of all: the dreaded phone call to his parents!

"Well, it started a few weeks ago", Izuku began. "Yeah?" Taro asked, asking him to continue, focusing his attention on the young Midoriya.

"I found this...thing that landed in my backyard. It could've been anything, really, but I wanted to make sure it was okay." The little boy continued, with the listening teacher beginning to really listen to the student beside him. A little bug-eyed, he motioned to Izuku, begging him to continue.

"Before I knew it, the thing jumped at me and landed on my arm. Kinda looked like a watch, a really fancy one too." Izuku stated, kinda hesitant to continue, having seen Someina keen on learning the truth.

Noticing Izuku's reluctance, Taro then told him, "Look, all the teachers here are worried about you, kid, myself included. We just want to understand why you're suddenly so good at all your classes, OK?"

Breathing in deeply, Izuku then answered, "This watch turned me into all kinds of weirdos. Last night I turned into this fish man by accident, I'm kinda glad I was in the tub when it happened."

Laughing a little, Taro then asked, "Which one of those guys made you so good at math then?" Coming in closer, Izuku whispered, "Some tiny frog thing, kinda grey, makes me pretty smart though."

"Could you show me?" Intrigued, Taro gently tried to persuade the young boy into shifting forms. Figuring it couldn't hurt, Izuku pressed a button on the watch, ready to transform.

Blushing again, Izuku hesitated. "Now what's up?" Mr. Someina asked, only to be retorted with, "I can't do it while you watch, if you'll pardon the pun, sir."

Nodding, the substitute chuckled a bit as he granted the little guy's request (his words, not mine). In no time flat, standing in the spot young Midoriya once stood was a familiar little frogman.

He then stated to Taro, "Now then, you can now grasp what I went through on a surface level. The question still remains, however, on the full details of this metamorphosis."

Putting the six-inch tall amphibian in a safe spot, namely a nearby desk, the substitute then placed the piece of paper in question near his student.

"Okay, kid, finish the equation." He said reassuringly. With a nod of assurance, young Midoriya soon got to work, even if it was kind of hard to grip the pencil now that he was at least six inches tall.

In a few minutes, three to be precise, the small genius finished at last. "Alright, we have the who, the what, and the how. The only things left are where and why." Taro explained.

"I finish my assignments at home like the others, the actual hard part is to explain the process to my human self before I change back," Izuku stated.

To a degree, Taro agreed, kids might be smarter than they seem, but they don't always grasp what's in front of them. "Well, aren't you just a regular _Flowers for Algernon_ ," he remarked.

Sending the young boy back to class, after he changed back into his regular self, of course, Mr. Someina and Izuku went to the teacher's lounge, thankfully easing the minds of the faculty with the confession Izuku gave.

However, Taro kept the equation away from his fellow teachers, dead set on proving himself right about something.

During breaks, he read the conglomeration of numbers and equations up and down until he thoroughly memorized them.

When he began searching for a similar equation online, Taro realized a key component: the beginning numbers were actually the formula for Adenine, Thymine, Cytosine, and Guanine. Why is that relevant? Because those are the building blocks for DNA, that's why!

Anyway, that wasn't it, however, as the rest of the equation soon showed Taro what exactly happens to DNA according to Izuku, the DNA for himself becomes reconfigured into that of other lifeforms, and ones not from Earth that the kid could recognize.

Mr. Someina, however, did and he knew exactly what to do. Grabbing the phone, he made a rather urgent and very important call that afternoon.

"Hello, Inko Midoriya speaking." The recipient replied. After a lengthy amount of time, for a ten-year-old anyway, Mrs. Midoriya told Izuku, "Honey, it's from the school, one of your teachers wants to talk!"

Carefully grabbing the phone from his mother, Izuku began to listen to Mr. Someina as he discussed his findings. " You know your little wrist thing makes you into guys with Quirks, right?" He asked.

"Yes, sir," Izuku replied, followed by Taro explaining, " I did some digging and found out something very interesting."

"What do you mean?" The kid inquired. " After almost an entire hour crunching those numbers you showed me this morning, it turns out your little super toy doesn't just alter your genes to give you powers, it makes you into something else entirely."

Izuku froze for a second, bracing himself for what his substitute teacher was going to say next. "Look, it's not my place to tell my students how to run their lives outside the classroom, but you should probably get me some more data on this watch thing you're wearing." Mr. Someina explained.

Before Izuku could reply, his teacher advised him, " If anybody asks, tell them it's for a school project this summer. I heard about your little habit with journals from the other teachers, they'll understand."

Figuring he had no other choice, and because he wanted to have fun this summer while also learning more about his new device, Izuku simply told his teacher, "Okay, I'll do my best sir."

Chuckling at the statement made by the spunky ten-year-old, Taro told Izuku, " Go beyond on that assignment, kid, Plus Ultra!"

Both sides hung up the phone, knowing the die had been cast. Izuku grabbed a freshly opened journal and wrote "Summer Project: Genetics Journal" on the brightly colored cover, as well as the symbol his watch had.

Taro Someina, meanwhile, simply dialed another number on the phone. "Hey, it's me." He told the other line. After almost getting his ear ruptured by his friend's excessive shouting, the substitute calmly stated, "Yeah, yeah, I should've called before, but I'm sure of it this time."

Opening a new app, Taro was in command of a few little robots, each resembling a relatively harmless and unnoticeable animal, but looked more like a menacing theme park animatronic. All of them, however, was built for a singular purpose: monitoring. Monitor what, or who in this case, you may ask?

A certain kid, of course. Inputting the available data he had on his target, Mr.Someina had him sighted under his nose.

With a constant eye now firmly placed on the young Midoriya, all Taro could say, unintentionally in unison with his student, "This is going to be fun."


End file.
